PULVERIZED COAL-FIRED BOILER AND PULVERIZED COAL COMBUSTION METHOD

摘要

An object of the present invention is to provide a pulverized coal-fired boiler for supplying efficiently air to a central part of a furnace and the neighborhood of a furnace wall, thereby promoting mixture with combustion gas, and reducing both NOx and CO. The present invention is characterized in that the main after air ports are structured so as to jet air having a large momentum for enabling arrival at the central part of the furnace, and the sub-after air ports are structured so as to jet air having a small momentum to the neighborhood of the wall face of the furnace, and a sectional center of each of the sub-after air ports is within a range from 1 to 5 times of a caliber of the main after air ports from a sectional center of each of the main after air ports. According to the present invention, the pulverized coal-fired boiler for supplying efficiently air to the central part of the furnace and the neighborhood of the furnace wall, thereby promoting mixture with combustion gas, and reducing both NOx and CO can be provided.